Challenges in the treatment of pediatric Mycoplasma pneumoniae pneumonia.

Mycoplasma pneumoniae (MP) is an important cause of community-acquired pneumonia in children and young adolescents. Despite macrolide antibiotics effectiveness as a first-line therapy, persistence of fever and/or clinical deterioration sometimes may complicate treatment and may even lead to severe systemic disease. To date, there is no consensus on alternative treatment options, optimal dosage, and duration for treating severe, progressive, and systemic MP pneumonia after macrolide treatment failure. Macrolide-resistant MP pneumonia and refractory MP pneumonia are the two major complex conditions that are clinically encountered. Currently, the vast majority of MP isolates are resistant to macrolides in East Asia, especially China, whereas in Europe and North America, whereas in Europe and North America prevalence is substantially lower than in Asia, varying across countries. The severity of pneumonia and extrapulmonary presentations may reflect the intensity of the host's immune reaction or the dissemination of bacterial infection. Children infected with macrolide-resistant MP strains who receive macrolide treatment experience persistent fever with extended antibiotic therapy and minimal decrease in MP-DNA load. Alternative second-line agents such as tetracyclines (doxycycline or minocycline) and fluoroquinolones (ciprofloxacin or levofloxacin) may lead to clinical improvement after macrolide treatment failure in children. Refractory MP pneumonia reflects a deterioration of clinical and radiological findings due to excessive immune response against the infection. Immunomodulators such as corticosteroids and intravenous immunoglobulin (IVIG) have shown promising results in treatment of refractory MP pneumonia, particularly when combined with appropriate antimicrobials. Corticosteroid-resistant hyperinflammatory MP pneumonia represents a persistent or recrudescent fever despite corticosteroid therapy with intravenous methylprednisolone at standard dosage. CONCLUSION:  This report summarizes the clinical significance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drugs, with a stepwise approach to the management of MP pneumonia recommended from the viewpoint of clinical practice. WHAT IS KNOWN: • Although MP pneumonia is usually a benign self-limited infection with response macrolides as first line therapy, severe life-threatening cases may develop if additional treatment strategies are not effectively implemented. • Macrolide-resistant and refractory MP pneumonia are two conditions that may complicate the clinical course of MP pneumonia, increasing the risk for exacerbation and even death. WHAT IS NEW: • This report summarizes the clinical relevance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drug therapies. • A practical stepwise approach to the management of MP pneumonia is developed based on a comprehensive analysis of existing evidence and expert opinion.

Joint association of sedentary behavior and physical activity with pulmonary function.

BACKGROUND: Sedentary behavior may influence the respiratory health, but the joint effects of sedentary behavior and physical activity on pulmonary function remains poorly elucidated. We aimed to estimate the association between sedentary behavior and physical activity with pulmonary function. METHODS: A total of 12,343 participants aged 12-79 years were analyzed from the U.S. NHANES 2007-2012. Participants were categorized into 16 groups according to the cross-tabulation of sedentary behavior time (0-4.0, 4.1-8.0, 8.1-12.0, and > 12.0 h/day) and moderate or vigorous physical activity (MVPA) (0, 1-149, 150-299, and ≥ 300 min/week). Generalized linear models were used to test the association of sedentary behavior and MVPA with pulmonary function. RESULTS: Participants with sedentary behavior > 4.0 h/day were negatively related to FEV1 (forced expiratory volume in 1 s) (ß ranging from -0.015 to -0.009, p < 0.05). Compared with the reference group (0 min of MVPA and > 12.0 h/day of sedentary behavior), the negative association of sedentary behavior ≤ 8.0 h/day with FEV1 may be reduced through appropriate MVPA (ß ranging from 0.019 to 0.030, p < 0.05). For sedentary behavior > 8.0 h/day, even MVPA ≥ 300 min/week may not decrease the negative relationships. Similar results were also observed in FVC (forced vital capacity) (ß ranging from 0.018 to 0.030, p < 0.05). In participants aged ≥ 45 years, the associations were more notable. CONCLUSION: This study indicated the sedentary behavior ≤ 4.0 h/day was a relatively healthy lifestyle for pulmonary function. Only below 8.0 h/day of sedentary behavior, the negative association with pulmonary function may be reduced through appropriate MVPA.

Precipitation pattern changed the content of non-structural carbohydrates components in different organs of Artemisia ordosica.

BACKGROUND: Non-structural carbohydrates (NSC) play a significant role in plant growth and defense and are an important component of carbon cycling in desert ecosystems. However, regarding global change scenarios, it remains unclear how NSCs in desert plants respond to changing precipitation patterns. [Methods] Three precipitation levels (natural precipitation, a 30% reduction in precipitation, and a 30% increase in precipitation) and two precipitation intervals levels (5 and 15 d) were simulated to study NSC (soluble sugar and starch) responses in the dominant shrub Artemisia ordosica. RESULTS: Precipitation level and interval interact to affect the NSC (both soluble sugar and starch components) content of A. ordosica. The effect of precipitation on NSC content and its components depended on extended precipitation interval. With lower precipitation and extended interval, soluble sugar content in roots increased and starch content decreased, indicating that A. ordosica adapts to external environmental changes by hydrolyzing root starch into soluble sugars. At 5 d interval, lower precipitation increased the NSC content of stems and especially roots. CONCLUSIONS: A. ordosica follows the "preferential allocation principle" to preferentially transport NSC to growing organs, which is an adaptive strategy to maintain a healthy physiological metabolism under drought conditions. The findings help understand the adaptation and survival mechanisms of desert vegetation under the changing precipitation patterns and are important in exploring the impact of carbon cycling in desert systems under global environmental change.

Urinary organophosphate metabolite concentrations and birth sizes among women conceiving through in vitro fertilization in Shanghai, China.

BACKGROUND: Few studies have examined the adverse birth sizes of preconception exposure to organophosphate pesticides (OPs) in women undergoing in vitro fertilization (IVF). OBJECTIVES: We investigated the relationship of preconception OP exposure with birth sizes among Chinese women undergoing IVF. METHODS: This study included 302 couples seeking infertility treatment in the China National Birth Cohort Study, from Shanghai, China, who gave birth to singleton infants between 2018 and 2021. Clinical data were collected from medical records. We measured the concentrations of six nonspecific dialkyl phosphates (DAP) metabolites of OPs [diethylthiophosphate (DETP), diethylphosphate (DEP), diethyldithiophosphate (DEDTP), dimethyldithiophosphate (DMTP), dimethylphosphate (DMP), and dimethyldithiophosphate (DMDTP)] in maternal urine. DMDTP and DEDTP were precluded from further analyses due to the low detection rates. Generalized linear models (GLMs) and weighted quantile sum (WQS) regression analyses were performed to examine the individual and joint effects of OP exposures on gestational age, birth weight, body length, and ponderal index. Odder ratio (OR) of preterm birth were estimated using logistic regression models. RESULTS: Women in the highest as compared with lowest quartile of DEP had shorter gestational age (ß = - 0.68; 95% CI = -1.24, -0.11). The association was modified by sex, with boys showing larger decreases in gestational age (ß = - 0.86; 95% CI = -1.60, -0.13). No associations were found between other DAP metabolites and birth sizes. Results from linear models with individual DAP metabolites were corroborated by the WQS regression where DEP had the largest contribution to the overall mixture effect on gestational age (weight = 0.70). Moreover, DEP concentration was associated with an elevated risk of preterm birth (OR = 1.35, 95% CI = 1.11, 2.25). CONCLUSION: Preconception DEP concentration was associated with shortened gestational age and increased risk of preterm birth, and the association was more pronounced among boys than girls.

Sequential Blood Purification for Pediatric Fatal Toxic Epidermal Necrolysis: A Case Series.

BACKGROUND: Extracorporeal therapy that included therapeutic plasma exchange (TPE) or continuous hemofiltration (CHF) for toxic epidermal necrolysis (TEN) syndrome was used in small number of patients. We aimed to describe the sequential mode of combined application of CHF and TPE in 3 TEN patients with multiple organ dysfunction (MODS) in pediatric intensive care unit. METHODS: Three patients with fatal TEN received sequential CHF and TPE due to unsatisfactorily conventional treatments. CHF was initiated and performed on a daily basis with 35-50 mL/kg.h replacement fluid at the rate of 3-5 mL/kg.min blood flow. CHF was temporarily interrupted for TPE, which was performed with exchange 1-1.5-fold of one body calculated plasma volume in each section. RESULTS: All 3 fatal TEN (with >30% involvement of body surface and MODS) following unsuccessful treatment with corticosteroids and intravenous immunoglobulin. Antibiotics were suspected in the TEN-triggered drugs. The range number of TPE sessions was 3-5 and the duration of CHF was from 120 h to 202 h. After initiation of TPE and CHF, blistering with extensive epidermal necrosis halted and the skin re-epithelialized within 2 weeks. Serum C-reactive protein, procalcitonin, tumor necrosis factor-α , and interlukin-6 decreased and percentage of natural killer cells increased in surviving children. Two patients survived to discharge and one case died due to nosocomial infection with multidrug-resistant Acinetobacter baumannii. CONCLUSION: After sequential TPE and CHF, skin lesions and inflammatory response improved in TEN. Our result indicates extracorporeal therapy could be used as an alternative modality for fatal pediatric TEN.

Association between triclosan exposure and obesity measures among 7-year-old children in northern China.

BACKGROUND: Triclosan (TCS) is a widely used synthetic antibacterial compound with ubiquitous human exposure. Animal studies have suggested the obesogenic effect of TCS exposure, but knowledge regarding its impacts on childhood obesity was limited. OBJECTIVE: To investigate the associations of TCS exposure with childhood obesity in northern China. METHODS: This study included 423 children who participated in the 7-year-old follow-up visits of Laizhou Wan Birth Cohort in Shandong, northern China. Children's TCS exposure were determined in spot urine samples via high performance liquid chromatography-tandem mass. Their height, weight, waist circumference, body fat percentage, body mass index (BMI), and waist-to-height ratio (WHtR) were measured or calculated. BMI z-score ≥ 85th percentile was defined as overweight/obesity, and WHtR ≥ 0.5 was considered to be abdominal obesity. Multivariable linear regressions, generalized linear models (GLMs), and multivariable logistic regressions were performed to examine the associations between TCS exposure and obesity measures in children. RESULTS: Linear regressions showed that TCS concentrations, when treated as continuous variables, were positively associated with BMI z-score (ß = 0.12, 95% CI: 0.01, 0.24) and body fat percentage (ß = 0.82, 95% CI: 0.13, 1.52). When TCS concentrations were categorized as a four-level ordinal variable, the results of GLMs were similar those of continuous variables and both of the positive trends were significant (p-trend = 0.049 for BMI z-score; p-trend = 0.023 for body fat percentage). Moreover, the higher TCS levels versus reference group were associated with an approximate 2-3 fold increased risk of abdominal obesity (p-trend = 0.044). CONCLUSION: Exposure to TCS was positively associated with obesity measures among 7-year-old children in northern, China. Given to the cross-sectional study design, a large prospective study is warranted to confirm our findings.

Optimal delivery timing for twin pregnancies: A population-based retrospective cohort study.

AIMS: The optimal timing of delivery for twin pregnancies remains controversial. This study examined the risks of adverse neonatal outcomes and neonatal deaths according to gestational age at delivery in order to determine the optimal gestational age of delivery for twin pregnancies. METHODS: This is a retrospective study of twin pregnancies delivered between 34 and 40 weeks of gestation from 1995 to 2000 in the United States. The primary outcomes evaluated were neonatal morbidity and mortality. The composite outcome of neonatal morbidity included the following variables: Apgar score lower than 7 at 5 minutes, assisted ventilation <30 minutes, assisted ventilation ≥30 minutes, hyaline membrane disease, meconium aspiration syndrome, neonatal seizures, birth injury, anaemia, and congenital malformations. Logistic regressions were applied to calculate adjusted odds ratios of the adverse outcomes according to the gestational week at delivery, with either individual twins or twin pairs as the unit of analysis. RESULTS: A total of 466 038 twins from 233 019 pregnancies from the US National Center for Health Statistics matched the multiple birth data set included in the study. The composite neonatal morbidity and mortality risks declined from 34 to 38 weeks of gestation and increased thereafter in both individual and pair twins stratified analyses. Amongst neonatal adverse outcomes, the risk of low Apgar score and hyaline membrane disease decreased progressively towards 38 weeks of gestation, only to increase again towards 40 weeks. The risk of meconium aspiration syndrome increased after 38 weeks, in both individual and pair twins. There were no differences in the risk of birth injury and neonatal seizures when stratified by gestational age. CONCLUSIONS: The optimal timing for twin delivery appears to be at 38 weeks of gestation, although individual maternal, foetal, and pregnancy characteristics should be considered when determining the best timing for delivery.

Exposure to Organophosphate Pesticides and Menstrual Cycle Characteristics in Chinese Preconceptional Women.

Organophosphates (OPs) are the most heavily used pesticides in China. The Chinese population, including preconceptional women, is highly exposed, yet little is known regarding the associations between OP exposure and menstruation in humans. We conducted a cross-sectional analysis in women preparing for pregnancy to investigate the relationship between biomarkers of OP exposure and menstrual cycle characteristics. From 2013 to 2015, 627 women visiting free preconception-care clinics at 2 maternity hospitals in Shanghai, China, were included. Information on menstrual cycle characteristics was obtained through questionnaires. OP exposure was assessed by measuring urine concentrations of 6 dialkylphosphate metabolites (dimethylphosphate, dimethylthiophosphate, dimethyldithiophosphate, diethylphosphate, diethylthiophosphate, and diethyldithiophosphate). The relationship between concentrations of dialkylphosphate metabolites and menstrual cycle characteristics was analyzed using multiple linear regression models and logistic regression models. Log-transformed levels of diethyl phosphate metabolites (the sum of diethylphosphate and diethylthiophosphate levels) were related to a higher risk of irregularity of menstrual cycles (adjusted odds ratio = 2.36, 95% confidence interval: 1.28, 4.34). Subjects with a higher concentration of diethyl phosphate metabolites (log-transformed) had a shorter duration of menstrual bleeding (adjusted ß = -0.33, 95% confidence interval: -0.64, -0.02). The findings suggest that OP exposure may be associated with alterations in menstrual function in preconceptional women.

Maternal preconception body mass index and time-to-pregnancy in Shanghai Women, China.

Previous studies suggested an association between female fertility and body size, but most of these studies were from Western countries and focused mainly on obesity. This study investigated the association between preconception body mass index (BMI) and time to pregnancy (TTP) in women planning to conceive from Shanghai, China. A total of 1,182 women aged 24-46 years were recruited from the Shanghai Birth Cohort between 2013 and 2015 and were followed up for 12 months. Preconception BMI was categorized as underweight, normal weight, and overweight/obesity according to the Chinese classification of BMI. Fecundability (FOR) and infertility (IOR) odds ratios were estimated using Cox (n = 1,092) and Logistic (n = 820) regression models, respectively. We found no differences in fecundability between underweight and overweight/obese women and normal-weight women. Furthermore, underweight and overweight/obese women did not have a higher risk of infertility compared with normal-weight women. Our findings suggest that non-optimal preconception BMI does not appear to influence female fecundability and infertility in Chinese women. These results should be interpreted with caution as they may be applicable only to women with demographic and anthropometric characteristics similar to our study population. Our findings need to be confirmed in other populations.

Insight into reduction of obacunone, and their ester derivatives as insecticidal agents against Mythimna separata Walker.

Here we have prepared a series of ester compounds of obacunone, a naturally occurring limonoid, isolated from plants such as Citrus and Dictamnus angustifolius. Their insecticidal activity was evaluated at 1 mg/mL against the pre-third-instar larvae of oriental armyworm (Mythimna separata Walker), a typical lepidopteran pest. When obacunone reacted with NaBH4, the ratio of two reduction products, C7α-hydroxyobacunone (2) and C7ß-hydroxyobacunone (3), was related to the reaction mixing solvents. C7α-Propionyloxybacunone (4b) and C7ß-(n)heptanoyloxybacunone (5g) exhibited the more promising insecticidal activity than their precursor obacunone and toosendanin.

Risk and protective factors for the development of childhood asthma.

Childhood asthma prevalence worldwide has been increasing markedly over several decades. Various theories have been proposed to account for this alarming trend. The disease has a broad spectrum of potential determinants ranging from genetics to lifestyle and environmental factors. Epidemiological observations have demonstrated that several important lifestyle and environmental factors including obesity, urban living, dietary patterns such as food low in antioxidants and fast food, non-breastfeeding, gut flora imbalance, cigarette smoking, air pollution, and viral infection are associated with asthma exacerbations in children. However, only environmental tobacco smoke has been associated with the development of asthma. Despite epidemiological studies indicating that many other factors are probably associated with the development of asthma, the relationships are not considered causal due to the inadequate evidence and inconsistent results from recent studies. This may highlight that sufficient data and exact mechanisms of causality are still in need of further study.

Association between prenatal exposure to polybrominated diphenyl ethers and young children's neurodevelopment in China.

The use of polybrominated diphenyl ethers (PBDEs) has been dramatically increasing over the last two decades in China. Animal studies suggest that prenatal exposure to PBDEs may result in neurodevelopmental deficits. Two hundred thirty-two participating mothers were recruited from a prospective birth cohort in rural northern China between September 2010 and February 2012. We analyzed 232 cord blood specimens for selected PBDE congeners and examined their association with children's developmental quotients (DQs) at 12 (n=192) and 24 (n=149) months of age based on the Gesell Developmental Schedules (motor, adaptive, language, and social domains). There were no substantial differences by demographic characteristics among the three time points: baseline, 12 and 24 months of age. Median cord blood levels of PBDE congeners 47, 99, 100, and 153 were 3.71, 6.70, 2.63, and 2.19 ng/g lipid, respectively. At 12 months of age, neither the individual nor total (the sum of BDEs 47, 99, 100, and 153) congener levels were associated with any of the four domain DQs. However, at 24 months of age, a 10-fold increase in BDE-99 levels was associated with a 2.16-point decrease [95% confidence interval (CI): -4.52, -0.20] in language domain DQs and a 10-fold increase in BDE-47 levels was associated with a 1.89-point decrease (95% CI: -3.75, -0.03) in social domain DQs. Prenatal exposure to PBDEs was associated with lower DQs in young children. The results contribute to the growing evidence that PBDEs could act as developmental neurotoxicants,and the findings have implications for children's environmental health in China.

Cu and Boron Doped Carbon Nitride for Highly Selective Oxidation of Toluene to Benzaldehyde.

A novel Cu and boron doped graphitic carbon nitride catalyst (Cu-CNB) was synthesized using cheap precursors and systematically characterized. The selective oxidation of toluene proceeded very smoothly over the catalyst at 70 °C using tert-butyl hydroperoxide (TBHP) as the oxidant to exclusively afford benzaldehyde. The catalyst can be used for at least five cycles without decrease in activity and selectivity.